Apparatus for conditioning hot wire gas detectors



L. F. BONNER Aug. 6, 1957 APPARATUS FOR CONDITIONING" H0' I WIRE GASDETECTORS Original Filed Oct. 19. 1953 Fla Iin um Wire /ndicalirigE/emenl 0 Snake A d/usler Me My/ alcohol 58 Solenoid Binder ControlValve 0 Melhy/alca/m/ container From drilling (mural/on I02 IN VHV TOR.Louis E Bonner,

BY 4AM FIG. 4.

nited States Patent Ofiiice 2,801,905 Patented Aug. 6, 1957 APPARATUSFOR CONDITIONING HOT WIRE GAS DETECTORS Louis F. Bonner, Houston, Tex,assignor, by mesne assignments, to Esso Research and EngineeringCompany, Elizabeth, N. .L, a corporation of Delaware Originalapplication October 19, 1953, Serial No. 386,845,

now Patent No. 2,713,010, dated July 12, 1955. Di- Xided ind thisapplication March 22, 1954, Seriai No.

3 Claims. (Cl. 23-255) The present invention is directed to a method andapparatus for conditioning a hot wire gas detector. More particularly,the invention is directed to a hot wire gas detector and means forconditioning the electrical element for use in formation sampling and inmud logging operations Where oil-emulsion muds are employed. In its morespecific aspects, the invention is concerned with method and apparatusfor removing combustible deposits from a hot wire gas detector used inlogging operations in which oil-emulsion muds are employed.

This application is a division of U. S. Serial No. 386,845, filedOctober 19, 1953, entitled Method and Apparatus for Conditioning HotWire Gas Detectors for Louis F. Bonner now U. S. Patent No. 2,713,010,issued July 12, 1955, entitled Method of Conditioning Hot Wire GasDetectors.

The present invention may be briefly described as a method forconditioning a hot wire gas detector employed in formation sampling andin mud logging operations in which an oil-emulsion mud and/or formationsamples are tested to determine the presence of hydrocarbons fromsubsurface earth formations. The specific feature of the invention iscontacting the hot Wire with vapors of a volatile oxygenated organiccompound such as the aliphatic alcohols, aliphatic ketones and aliphaticethers, these oxygenated compounds having a carbon chain in which thereare no more than three carbon atoms. The vapors are then ignited wherebyany deposits on the hot wire are removed by combustion of the volatileoxygenated organic compounds.

The present invention also is concerned with apparatus for use in mudand sample logging in which oil-emulsion minds are employed comprising ahousing defining a chamber having an electrical element arranged in thechamber. This element becomes fouled with combustible deposits on use insaid mud logging operations where oil-emulsion muds are employed. Theapparatus comprises a container adapted to receive a body of a volatileoxygenated organic compound selected from the group consisting of thealiphatic alcohols, ketones and ethers having a carbon chain of no morethan three carbon atoms. The container is provided with means forinjecting air thereinto at a lower point in the container below thesurface of the body. A conduit is connected to the container at an upperpoint remote from the lower point and above the surface of the body.This conduit projects into the container and is partially orsubstantially enclosed by bafiie members in the container which prevententry of the liquid into the conduit. The conduit is connected to anintroducing means for introducing the combustible mixture into thechamber. The chamber is provided with means for energizing theelectrical element to ignite the mixture and burn off combustibledeposits. The

.air injectionmeans may comprise a plunger and a biasing means, such asa spring, for causing the plunger to inject air in the container.Likewise, the air injection means 2 may comprise a solenoid-operatedplunger which is electrically energized.

The invention will be further illustrated by reference to the drawing inwhich:

Fig. 1 is an illustration of a preferred embodiment showing the biasedplunger for injecting air into the container;

Fig. 2 is an illustration of a solenoid operated plunger;

Fig. 3 is a wiring diagram of the hot wire detector; and

Fig. 4 shows the application of the apparatus of the present inventionto mud logging.

Referring now to the drawing and particularly Fig. 1, numeral 11designates, ahot wire detecting device which is provided with electricalleads 12 connected to a recorder or indicator 13 of the balanced-bridgetype. The indicator 13 has a scale 14 and an indicating means 15 to showthe deflection of the instrument. The indicator 13 is provided withelectrical leads 18a and 18b for energizing the hot wire from a batterysuch as 86.

The apparatus includes a container 19 in which is arranged a body of thevolatile oxygenated organic compound 20. The container is provided withan inlet pipe 21 which leads to a lower part of the container below thesurface 22 of the body of volatile oxygenated organic compound. The pipe21 is connected by a coupling 23 to a check valve 24 which, in turn, isconnected by conduit 25 to a plunger mechanism generally indicated bythe numeral 26 and including a piston or plunger 27, a plunger shaft 28and a biasing means, such as spring 29, which normally urges the plunger27 downwardly. The lower end of the spring 29 bears against the plunger27 while the upper end is confined by an annular sleeve 30. The plungermechanism generally indicated by 26 has openings 31' in end 31 throughwhich the shaft 28 projects. The shaft 28 is provided with a shoulder32. Arranged adjacent the shoulder 32 is a cam or eccentric 33 connectedby means of a shaft 34 to a clock mechanism or suitable other energizingmeans.

Connected to the container 19 is a conduit 35 which projects into theupper part of the container 19. The projection of the conduit 35 in thecontainer 19 is partially or substantially enclosed by bafiie members 36and 37 which serve to prevent entry of liquid in the conduit 35. Theconduit 35 is connected to a check valve 39 for introducing gaseousmixture into the indicating element 11. The indicator element isprovided with ports 40 to allow the gaseous mixture to circulate freelyover the hot wire or detecting element and for withdrawal of thecombustion products.

The container 19 is provided with a closure member 41 which isthreadably connected by threads 42 to the container, the conduit 35passing through. the closure member 41.

The check valves 24 and 39 are constructed similarly and are comprisedof spheres or balls 43 which are designed to seat against seats 44. Thespheres 43 are biased against the seats 44 by means of a biasing meansor spring 45 arranged on a spring member 46, the spring 45 and thespring member 46 being mounted on a plate 47 arranged in the checkvalves 24 and 39.

Referring now to Fig. 2 in which the air injecting means is asolenoid-operated plunger, the numeral 50 designates generally thesolenoid-operated mechanism in which is arranged a plunger 51, providedwith O-ring seals 51a and 51b, which is normally biased in an upwardposition by a spring 52. The plunger 51 is provided with a shaft 53 onwhich is arranged a shoulder 54. Aclosure member 55 through which theshaft 53 projects is threadably connected by threads 56 to the solenoidmember 50, the shaft 53 being slidably sealed by an O-ring 57. Woundaround the upper end of the member 50 is a sole noid winding 53 which isconnected by electrical connections 59 and 60 to a source of powerillustrated by a battery 61. Arranged in the circuit is a solenoidswitch 62 which is connected to a snap switch assembly 63 which carriesa stroke adjustment assembly 63a and which has a projecting means 63b,the snap switch assembly and the solenoid switch being connected by aspring 64.

The solenoid assembly 50 is provided with first and second air intakecheck valves 65a and 65b, respectively, having spheres 66a and 66bbiased against the seats 67a and 67b by means of springs 68a and 68b. Ableeder control valve 69 is provided to fit against the seat '70 whichis actuated manually by a valve wheel 71, the valve housing '72 beingprovided with a port 73. Thus bleeder valve 60 controls the rate ofreturn of plunger 51 and, therefore, the time cycle of injection.

Referring now to Fig. 3, it will be seen that the hot wire gas detectoris a Wheatstone bridge 85 having a platinum wire 80 arranged in acircuit. The Wheatstone bridge comprises the platinum wire 80, a fixedresistor 81, a balancing resistor 82 and a compensating element 83 beingconnected by means of electrical connections 12 to the recorder ordetector element 13. The Wheatstone bridge, which is generally indicatedby the numeral 85, is provided with a source of power, such as battery86, and connected thereto by means of electrical connections 13a and18b. An ammeter 89 is arranged in electrical connection 18a and isprovided with ampere control means, such as a resistor 90.

The apparatus of the present invention may suitably housed in mudlogging operations, such as illustrated in Fig. 4, in which a mud line100 is connected to a drilling operation, not shown, and delivers mud toa mud pit, not shown. The mud line 100 is provided with a standpipe 101which allows the mud to rise therein as a column 102 due to the pressurehead. Above the mud column 102 in standpipe 101 there is a vaporousatmosphere 104 in which the indicator element 11 is arranged as shown.The-standpipe 101 is provided with a closure member 103.

Carried through the closure member 103 are the electrical connectingmeans 12 leading to the recorder 13 which has been described. Alsocarried through the closure member 103 is a conduit 38 including thecheck valve 39 which is connected to the conduit 35. The electricalconnections 12 may be carried either through the closure member 103 orthrough the wall of the standpipe 101. Bathe d diverts mud from the line100 through the standpipe 101 and assures continuous mud supply to thesystem.

The device of the present invention works in the following manner withrespect to Figs. 1 and 3:

For the purpose of this description, it will be assumed that the hotwire element 80 which may be a fine platinum wire having an overallcoiled length of A to of an inch has become fouled with depositsresulting from well logging operations The device of Fig. l is connectedto the indicating element 11 including a platinum wire 80 and air isinjected into the container 19 by operating the shaft 34, as theeccentric or cam 33 rotates in the direction indicated by the arrow, thecam bears against the shoulder 32 raising the shaft 28 embracing thespring 29. As the cam or eccentric continues the retation, the collar $2is released allowing air to be forced downwardly by the plunger 27, theair being sucked or drawn through the openings 31 in member 31 past theplunger 27 as it is raised by the rotation of the cam. When the plungeris released from the high part of the cam, the plunger is forceddownwardly and the air is forced through the deck valve 24 causing thesphere 43 to bear against the spring 45. The air bubbles upwardlythrough the body 20 of the volatile oxygenated organic compound andthence into the conduit 35, the baffies 3:6 and 37 prevent any liquiddue to breaking bubbles or from entrainment from passing into theconduit 35 and thence through the check valve 39 into the indicator 11into contact with the hot wire 80 which is energized by r electricalconnections 18 and 18a by battery 06. As the combustible deposits areremoved from the wire, the indicating means 15 will become deflected andthen returned to zero.

The device of Fig. 2 operates in a similar manner to supply air to thecontainer 19. With reference to Fig. 2 with the plunger down and thespring 52 compressed, the switch 62 controlling the solenoid is openallowing the plunger to be forced upwardly by the pressure of thespring. The speed of the retreating plunger is controlled by the openingand closing of the bleeder control valve 6% which allows air to beexhausted by the port 73. As the plunger shaft 53 approaches the top ofthe assembly 50, air is drawn in below piston 5, through second checkvalve 65b by the sphere 66b moving off seat 67b and the strokeadjustment screw 63a is then contacted and caused to rotate. As thisadjustment rotates clockwise, spring 6 will move solenoid switch 62 intoa closed position thereby actuating the solenoid again and pulling theplunger shaft 53 downwardly compressing the spring 52, air having beentrapped below the plunger 51 on the upstroke of the plunger 51 which isthen forced down causing air to pass through the first check valve 65aforcing the sphere 66a otf the seat 67a. The operation with respect toFig. 2 thereafter is similar to that of Fig. 1.

In the operation with respect to Fig. 3, the mud flowing through the mudline 100 will rise as a column 102 in standpipe 1100 and provide avaporous atmosphere 103. The detector element 11 including the platinumwire is in contact through ports 40 with the vaporous atmosphere. Byenergizing the hot wire, the presence of combustible vapors in theatmosphere 104 may be determined on the scale 14 by the indicating means15.

When the hot wire 80 becomes fouled with combustible products volatileoxygenated organic compounds are introduced by introducing means 38 ashas been described and the combustible deposits removed from the wire80. Thereafter the mud logging operation may be resumed, the removal ofcombustible deposits being conducted periodically and automatically asoccasion requires.

The present invention is particularly adaptable for use in mud loggingoperations where a hot wire gas detector is used and where the wirebecomes fouled with deposits. This is sometimes encountered in mudlogging where a normal drilling mud, such as an aqueous mud, is employedbut more frequently is encountered where oil-emulsion muds are used. Infact, heretofore it has been substantially impossible to conduct mudlogging operations where oil-emulsion muds have been used. Efforts havebeen made to remove deposits from platinum wires using hot wiredetectors by injecting vapors of gasoline and light hydrocarbons intothe detector element and then energizing the hot wire to burn oif thedeposits. This has been unsuccessful in that the long chain hydrocarbonseither do not burn with a sufliciently hot flame or leave in themselvesa deposit which interferes with the accuracy of the device.

in mud logging where a well is drilled with oil-emulsion mud, the hotwire gas detector rapidly becomes inoperative due to the coating formedon the element. Prior to the present invention, the remedy was to removethe element or either replace it or clean it by burning out usinghydrocarbon vapors. As will be clear, this requires considerable timeand had to be performed many times a day, such as possibly every 15minutes. The present invention obviates this difiiculty since the deviceof the present invention may be connected to the hot wire detector andautomatically and periodically employed to condition the element withoutremoving it from the gas collection chamber. Thus the cam, such asdescribed in Fig. 1, may be run at a controlled speed by a suitable gearwhich may be variable from one revolution in 5 minutes to 1 revolutionan hour and likewise with respect to the solenoid actuated embQdiment.

While especially useful in operations involving oil emulsion roads, thepresent invention is also applicable to use in logging drill cuttings,examination of bottom hole and side wall cores, aqueous drilling mud,and any media which comes into contact with subsurface formations whichmay contain hydrocarbons.

The nature and objects of the present invention having been completelydescribed and illustrated, What I wish to claim as new and useful and tosecure by Letters Patent is:

1. A system for conditioning a gas detector comprising a detectorhousing having an electrical element arranged therein for ignitinggaseous mixtures, an electrical circuit including a source of electricalenergy and indicator means connected to said electrical element, saidindicator means being adapted to indicate the conditioning of saidelectrical element, a closed container, a body of a volatile oxygenatedorganic compound selected from the group consisting of the aliphaticalcohols, ketones, and others having a carbon chain of no more thanthree carbon atoms located in said container, a first conduit having oneend extending into said container to substantially below the surface ofsaid body, a cylinder, means for admitting air to said cylinder, aplunger slidably arranged in said cylinder, biasing means positioned insaid cylinder adapted to urge said plunger in one direction, energizingmeans operatively associated with said plunger adapted to periodicallymove said plunger against the urging of said biasing means, the otherend of said first conduit fluidly communicating with said cylinder, afirst check valve positioned in said conduit adapted to permit fluidflow from said cylinder to said container and to prevent fluid flow fromsaid container to said cylinder, a second conduit fluidly communicatingthe interior of said container above said body and said detectorhousing, a second check valve positioned in said second conduit adaptedto permit fluid flow between said container and said detector housingand to prevent fluid flow between said detector housing and saidcontainer, and baffle means positioned in said container adjacent saidsecond conduit adapted to prevent liquid flow into said second conduit.

2. A system as recited in claim 1 wherein said plunger energizing meansis a clock actuated cam.

3. A system as recited in claim 1 wherein said plunger energizing meansincludes a solenoid.

References Cited in the file of this patent UNITED STATES PATENTS505,700 Cornish Sept. 26, 1893 620,646 Filley Mar. 7, 1899 813,671Schlatter Feb. 27, 1906 2,037,249 Morgan et a1. Mar. 9, 1937 2,363,478Boeke Nov. 28, 1944 2,449,485 Johnson Sept. 14, 1948 FOREIGN PATENTS561,444 Great Britain May 19, 1944

1. A SYSTEM FOR CONDITIONING A GAS DETECTOR COMPRISING A DETECTORHOUSING HAVING AN ELECTRIAL ELEMENT ARRANGED THEREIN FOR IGNITINGGASEOUS MIXTURES, AN ELECTRICAL CIRCUIT INCLUDING A SOURCE OF ELECTRICALENERGY AND INDICATOR MEANS CONNECTED TO SAID ELECTRICAL ELEMENTS, SAIDINDICATOR MEANS BEING ADAPTED TO INDICATE THE CONDITIONING OF SAIDELECTRICAL ELEMENT, A CLOSED CONTAINER, A BODY OF A VOLATILE OXYGENATEDORGANIC COMPOUND SELECTED FROM THE GROUP CONSITING OF THE ALIPHATICALCOHOLS, KETONES, AND ETHER HAVING A CARBON CHAIN OF NO MORE THAN THREECARBON ATOMS LOCATED IN SAID CONTAINER, A FIRST CONDUIT HAVING ONE ENDEXTENDING INTO SAID CONTAINER TO SUBSTANTIALLY BELOW THE SURFACE OF SAIDBODY, A CYLINDER, MEANS FOR ADMITTING AIR TO SAID CYLINDER, A PLUNGERSLIDABLY ARRANGED IN SAID CYLINDER, BIASING MEANS POSITIONED IN SAIDCYLINDER ADAPTED TO URGE SAID PLUNGER IN ONE DIRECTION, ENERGIZING MEANSOPERATIVELY ASSOCIATED WITH DAIS PLUNGER ADAPTED TO PERIODICALLY MOVESAID PLUNGER AGAINST THE URGING OF SAID BIASING MEANS, THE OTHER END OFSAID FIRST CONDUIT FLUIDLY COMMUNICATING WITH SAID CYLINDER, A FIRSTCHECK VALVE POSITIONED IN SAID CONDUIT ADAPTED TO PERMIT FLUID FLOW FROMSAID CYLINDER TO SAID CONTAINER AND TO PREVENT FLUID FLOW FROM SAIDCONTAINER TO SAID CYLINDER, A SECOND CONDUIT FLUIDLY COMMUNICATING THEINTERIOR OF SAID CONTAINER ABOVE SAID BODY AND SAID DETECTOR HOUSING, ASECOND CHECK VALVE POSITIONED IN SAID SECOND CONDUIT ADAPTED TO PERMITFLUID FLOW BETWEEN SAID CONTAINER AND SAID DETECTOR HOUSING TO PREVENTFLUID FLOW BETWEEN SAID DETECTOR HOUSING AND SAID CONTAINER, AND BAFFLEMEANS POSITIONED IN SAID CONTAINER ADJACENT SAID SECOND CONDUIT ADAPTEDTO PREVENT LIQUID FLOW INTO SAID SECOND CONDUIT.